Laser removing method for damaged coating on surface of metal base material and application of laser removing method

Abstract

The invention provides a laser removing method for a damaged coating on the surface of a metal base material and application of the laser removing method. The laser removing method comprises the following steps that the thickness and the shape of a damaged coating on the surface of a metal base material are obtained, working parameters of a laser device are determined, laser spots generated by the laser device are concentrated on the damaged coating area on the surface of the metal base material, and laser removing treatment is conducted; wherein the working parameters comprise laser power, laser pulse width, line spacing and laser frequency. According to the method, accurate control over the removing process can be achieved, the working parameters of the laser device are adjusted based on the parameters of the damaged coating, the cleaning depth and range can be accurately controlled, customized cleaning can be conducted according to different requirements when the damaged coating is removed, the damaged coating can be completely removed, and excessive cleaning or damage can be avoided. And for some thicker metal coatings or coatings which are difficult to remove at one time, the laser cleaning can be carried out repeatedly, and the damage to the base material is avoided.

Description

Technical Field

[0001] The invention belongs to the technical field of metal surface coating cleaning, and specifically relates to a laser cleaning method for damaged coating on the surface of a metal substrate and application thereof. Background Art

[0002] With the exploration and development of large deep-sea oil and gas fields in my country, the application of deep-sea drilling rigs, drilling and production platforms, and floating production storage and unloading units will become increasingly widespread. These marine engineering equipment face severe marine-atmospheric corrosion environments during service. In harsh environments, the contradiction between the service environment and the unreasonable service life of steel is very prominent. During service, the steel structure fails due to the harsh environment, especially in the application of harsh environments such as marine engineering and oil pipelines. Every year, the steel that fails due to corrosion and wear has caused considerable economic losses to my country and even the world, and also caused a lot of resource waste. In this regard, domestic and foreign researchers have tried to improve this situation through surface modification engineering. Metal-based anti-slip coatings have the advantage of long service life. Due to its good wear resistance, corrosion resistance and stable friction coefficient, metal-based anti-slip coatings are widely used in industrial production, offshore platforms and ship decks.

[0003] Inconel 625 is a widely used thermal spray metal coating. It was first developed in the 1960s. It has a face-centered cubic structure and a single structure (austenite structure). It is a typical nickel-based high-temperature corrosion-resistant alloy with stable performance and good comprehensive performance, mainly manifested in: (1) It has excellent oxidation resistance in service and is generally not easily oxidized by the medium under normal temperature conditions; (2) It has good corrosion resistance and is not easily corroded in harsh corrosive media environments; (3) Inconel 625 not only has excellent plasticity and weldability, but also has good machinability and can be applied to various processing methods and a wide range; (4) Under the condition of ensuring equivalent performance, the cost is lower than that of Co-based coatings; Because Inconel 625 alloy has good comprehensive properties and still exhibits excellent corrosion resistance and oxidation resistance under high temperature conditions, it is often used as a modified coating to protect the base metal in surface modification projects.

[0004] However, metal coatings can also break and become ineffective, and in this case, the damaged coating needs to be removed for repair. Metal coatings have a high bonding strength with materials, and a common removal method is sandblasting, which cleans the metal surface by spraying abrasives such as sand at high speed to remove oxide scale, rust, etc. However, sandblasting will produce a large amount of dust, which pollutes the environment and may cause a certain degree of damage to the metal surface. In addition, sandblasting equipment will produce a lot of noise during operation, causing noise pollution to operators and the surrounding environment. The purchase and maintenance costs of sandblasting equipment are high. At the same time, a large amount of sand and other materials are consumed during the sandblasting process, which will increase the cost of removing metal coatings.

[0005] Therefore, there is an urgent need to find a new method for removing damaged coatings that can efficiently remove damaged coatings while meeting environmental protection requirements. Summary of the invention

[0006] In view of the deficiencies of the prior art, the purpose of the present invention is to provide a laser removal method for damaged coatings on the surface of metal substrates and its application. The laser removal method provided by the present invention can achieve precise control of the cleaning process. By adjusting the working parameters of the laser based on the parameters of the damaged coating, the depth and range of cleaning can be accurately controlled. This allows customized cleaning to be performed according to different needs when removing the damaged coating, which can not only completely remove the damaged coating, but also avoid excessive cleaning or damage to the metal substrate. For some thicker metal coatings or coatings that are difficult to remove in one go, laser cleaning can be repeated multiple times to gradually remove the damaged coating without damaging the substrate.

[0007] In order to achieve the purpose of the invention, the present invention adopts the following technical solutions:

[0008] In a first aspect, the present invention provides a laser removal method for a damaged coating on a metal substrate surface, the laser removal method comprising the following steps:

[0009] The thickness and shape of the damaged coating on the surface of the metal substrate are obtained, and the working parameters of the laser are determined so that the laser spot generated by the laser is concentrated on the damaged coating area on the surface of the metal substrate for laser cleaning.

[0010] The working parameters include laser power, laser pulse width, line spacing and laser frequency.

[0011] The laser cleaning method provided by the present invention can achieve precise control of the cleaning process. By adjusting the working parameters of the laser based on the parameters of the damaged coating, the depth and range of cleaning can be precisely controlled. This allows customized cleaning to be performed according to different needs when removing the damaged coating, which can not only completely remove the damaged coating, but also avoid excessive cleaning or damage to the metal substrate. For some thicker metal coatings or coatings that are difficult to remove in one go, laser cleaning can be repeated multiple times to gradually remove the damaged coating without damaging the substrate.

[0012] Preferably, the material of the damaged coating includes Inconel 625 material or metal-based ceramic material.

[0013] It should be noted that Inconel 625 material is a solid solution strengthened nickel-based deformable high temperature alloy with molybdenum and niobium as the main strengthening elements. It has excellent corrosion resistance and oxidation resistance, good tensile and fatigue properties from low temperature to 980℃, and is resistant to stress corrosion in salt spray atmosphere. Therefore, it can be widely used in the manufacture of aircraft engine parts, aerospace structural parts and chemical equipment.

[0014] Preferably, the metal-based ceramic material includes a metal component and a ceramic component. For example, the metal component may be Ni60A, the ceramic component may be Al2O3, and the mass ratio of the metal component to the ceramic component may be 17:3.

[0015] Preferably, the thickness of the damaged coating is 100-300 μm, for example, 100 μm, 150 μm, 200 μm, 250 μm or 300 μm.

[0016] It should be noted that the shape of the damaged coating is caused by the use during service.

[0017] Preferably, the laser comprises a nanosecond pulse laser.

[0018] It should be noted that a nanosecond pulse laser is a device that can generate nanosecond pulse width lasers, and its operation is based on the principle of stimulated radiation of lasers. In the working material of the laser, the particles in the working material are transitioned from a low energy state to a high energy state through the excitation of external energy (such as light excitation or electrical excitation from a pump source), forming a particle number inversion distribution. When a certain inversion threshold is reached, the particles in the high energy state will return to the low energy state in the form of stimulated radiation, while releasing photons with the same frequency, phase, and direction as the excitation light. These photons are continuously reflected and amplified in the laser's resonant cavity, and eventually form laser output. The generation of nanosecond pulses is usually achieved by introducing a certain modulation mechanism in the resonant cavity, such as Q-switching technology or mode-locking technology, to temporally modulate the generation of the laser, thereby obtaining nanosecond pulse output.

[0019] Preferably, the laser pulse width of the laser is 1-500ns, for example, it can be 1ns, 10ns, 50ns, 100ns, 200ns, 300ns, 400ns or 500ns, etc., preferably 5-20ns.

[0020] In the present invention, the laser pulse width within a suitable range helps the laser act on the material surface more evenly, and there will be no local over-cleaning or under-cleaning, so that the surface after cleaning has good appearance quality; and it also helps to reduce the impact of the laser cleaning process on the microstructure of the material, ensuring that the laser cleaning can effectively remove the coating while minimizing the damage to the substrate surface, ensuring the performance and integrity of the substrate; secondly, the suitable pulse width can also achieve better flatness and improve the surface quality of the material after cleaning. In addition, under the appropriate pulse width, laser cleaning can remove pollutants with higher efficiency, reduce energy consumption and cleaning time.

[0021] Preferably, the laser power is 150-250 W, for example, 150 W, 175 W, 200 W, 225 W or 250 W.

[0022] In the present invention, the laser power within a suitable range helps to improve the effect of laser cleaning. The appropriate laser power can not only remove pollutants and improve the cleaning efficiency, but also improve the surface properties of the substrate to a certain extent. When the laser power is too low, the cleaning speed will slow down, resulting in low cleaning efficiency, and pollutants may not be effectively removed, resulting in incomplete cleaning. When the laser power is too high, the substrate may be overheated, deformed or even damaged. For this reason, more time may be required to adjust the laser parameters to avoid damage to the substrate, but this will reduce the cleaning efficiency. Therefore, selecting the appropriate laser power can improve the cleaning efficiency while ensuring the cleaning effect.

[0023] Preferably, the laser frequency is 1-5000kHz, for example, it can be 1kHz, 10kHz, 100kHz, 500kHz, 1000kHz, 2000kHz, 3000kHz, 4000kHz or 5000kHz, etc., preferably 2000-2500kHz.

[0024] In the present invention, the laser frequency in the appropriate range helps to significantly improve the efficiency of laser cleaning. When the frequency is too low, the number of laser pulses per unit time is small and the cleaning speed is slow. However, a frequency that is too high may cause the laser energy to disperse and the cleaning effect to be poor; the appropriate laser frequency helps to protect the substrate being cleaned. If the frequency is too high, the substrate may absorb too much heat, causing damage to the substrate. If the frequency is too low, the pollutants may not be effectively removed. In the subsequent cleaning process, the laser energy may need to be increased, increasing the risk of damage to the substrate; the appropriate laser frequency can make the laser cleaning more uniform and thorough. Different removal objects and substrates respond differently to the laser frequency. By selecting the appropriate frequency, the laser energy can better interact with the removal object and improve the cleaning quality; the appropriate laser frequency can reduce the energy consumption during the laser cleaning process. When the frequency is too high, the laser equipment needs to consume more energy to generate high-frequency pulses, and this part of the energy may not be fully and effectively used for cleaning. In summary, selecting an appropriate frequency can reduce the energy consumption of the equipment and save energy costs while ensuring the cleaning effect.

[0025] Preferably, the line spacing is 0.008-0.012 mm, for example, 0.008 mm, 0.01 mm or 0.012 mm, etc. The line spacing of a laser refers to the distance between the laser spectral lines output by the laser.

[0026] In the present invention, the line spacing of the laser directly affects the cleaning accuracy and quality.

[0027] Preferably, the laser scanning interval of the laser is smaller than the diameter of the laser spot.

[0028] It should be noted that the laser scanning spacing refers to the distance between two adjacent laser scanning paths in applications such as laser scanning processing or detection.

[0029] The present invention limits the laser scanning spacing of the laser to be smaller than the diameter of the laser spot, which has the following effects: 1) improving processing accuracy. When the laser scanning spacing is smaller than the spot diameter, the processing area can be more finely controlled, and problems such as rough processing edges and dimensional deviations caused by excessive scanning spacing can be avoided, thereby achieving nanometer-level or even higher precision processing; 2) the laser energy is more evenly distributed on the material, and the heat can be diffused more effectively, thereby reducing the range of the heat-affected zone and ensuring that the substrate maintains good physical and chemical properties after the damaged coating is removed; 3) a smaller laser scanning spacing can make the coating surface smoother and flatter.

[0030] Preferably, the diameter of the laser spot is 60-100 μm, for example, 60 μm, 70 μm, 80 μm, 90 μm or 100 μm.

[0031] In the present invention, a suitable range of laser spot helps to improve the effect of laser cleaning. During the laser cleaning process, the diameter of the laser spot directly affects the interaction area between the laser and the surface of the object to be cleaned. If the spot diameter is too small, it may lead to low cleaning efficiency and require more time and energy to complete the cleaning task; if the spot diameter is too large, it may affect the surrounding areas that do not need to be cleaned, reducing the cleaning accuracy. Therefore, a suitable laser spot diameter can better control the distribution of laser energy on the surface to be cleaned, improve cleaning efficiency, and better protect the substrate material during the cleaning process.

[0032] Preferably, the operating parameters of the laser also include a scanning rate.

[0033] Preferably, the scanning rate is 1-16000 mm / s, for example, it can be 1 mm / s, 10 mm / s, 100 mm / s, 500 mm / s, 1000 mm / s, 3000 mm / s, 5000 mm / s, 7000 mm / s, 10000 mm / s or 15000 mm / s, etc., preferably 50-100 mm / s.

[0034] Preferably, the operating parameters of the laser also include a scanning path and a scanning number.

[0035] Preferably, the scanning path comprises a zigzag shape or a zigzag shape.

[0036] Preferably, the number of scans is 1-5 times, for example, 1 time, 2 times, 3 times, 4 times or 5 times.

[0037] Preferably, the laser cleaning method comprises the following steps:

[0038] (1) Place a metal substrate with a damaged coating on its surface directly below the laser head of a laser, and keep the plane where the damaged coating is located parallel to the platform surface of the laser. At the same time, control the surface of the metal substrate to be 20-30 cm away from the laser head (for example, 20 cm, 25 cm, or 30 cm, etc.).

[0039] (2) Determine the material type, thickness and shape of the damaged coating on the surface of the metal substrate, and then determine the working parameters of the laser so that the laser spot generated by the laser is concentrated on the damaged coating area on the surface of the metal substrate for laser cleaning.

[0040] The material of the damaged coating includes Inconel 625 material or metal-based ceramic material, and the thickness of the damaged coating is 100-300 μm; the working parameters include laser power, laser pulse width, line spacing, laser frequency, laser wavelength, scanning rate, scanning path and number of scans, the laser power is 150-250 W, the laser pulse width is 1-500 ns, the line spacing is 0.008-0.012 mm, the laser frequency is 1-5000 kHz, the laser wavelength is 1064 nm, the scanning rate is 1-16000 mm / s, the scanning path includes a zigzag or a zigzag, and the number of scans is 1-5 times; the laser scanning spacing of the laser is smaller than the diameter of the laser spot, the diameter of the laser spot is 60-100 μm, and the overlap rate of the laser spot is 65-75% (for example, it can be 65%, 70% or 70%, etc.).

[0041] (3) After the laser cleaning treatment in step (2) is completed, the surface of the metal substrate is purged and then cooled to room temperature to obtain a metal substrate with the damaged coating removed.

[0042] It should be noted that the overlap rate of the laser spots refers to the ratio of the area of ​​the overlapping parts between adjacent laser spots to the area of ​​a single spot during laser processing or scanning.

[0043] In a second aspect, the present invention provides an application of the laser cleaning method as described in the first aspect in the field of metal surface coating cleaning.

[0044] The numerical range described in the present invention not only includes the point values ​​listed above, but also includes any point values ​​between the above numerical ranges that are not listed. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the range.

[0045] Compared with the prior art, the present invention has the following beneficial effects:

[0046] The laser cleaning method provided by the present invention can achieve precise control of the cleaning process. By adjusting the working parameters of the laser based on the parameters of the damaged coating, the depth and range of cleaning can be precisely controlled. This allows customized cleaning to be performed according to different needs when removing the damaged coating, which can not only completely remove the damaged coating, but also avoid excessive cleaning or damage to the metal substrate. For some thicker metal coatings or coatings that are difficult to remove in one go, laser cleaning can be repeated multiple times to gradually remove the damaged coating without damaging the substrate. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 This is an optical comparison diagram of the metal substrate provided in Example 1 of the present invention before and after the damaged coating is removed.

[0048] Figure 2 Optical comparison diagrams of the metal substrate provided in Example 2 of the present invention before and after removing the damaged coating.

[0049] Figure 3 Optical comparison diagrams of the metal substrate provided in Example 3 of the present invention before and after removing the damaged coating.

[0050] Figure 4 Optical comparison diagrams of the metal substrate provided in Comparative Example 1 of the present invention before and after removing the damaged coating. Detailed implementation manners

[0051] The technical solutions of the present invention will be further described below through specific implementation manners. Those skilled in the art should understand that the embodiments are only for helping to understand the present invention and should not be regarded as specific limitations to the present invention.

[0052] It should be noted that the following room temperature refers to 25°C.

[0053] Example 1

[0054] The coating on the surface of the metal substrate provided in this example was prepared by atmospheric plasma thermal spraying of Inconel 625 metal wire material on a Q235 metal plate.

[0055] This example provides a method for laser removal of damaged coatings on the surface of a metal substrate. The laser removal method includes the following steps:

[0056] (1) Place the metal substrate with a damaged coating on the surface directly below the laser head of a nanosecond pulsed laser, and keep the plane where the damaged coating is located parallel to the platform surface of the nanosecond pulsed laser. At the same time, control the surface of the metal substrate to be 25 cm away from the laser head.

[0057] (2) Determine the material type, thickness, and shape of the damaged coating on the surface of the metal substrate, and then determine the working parameters of the nanosecond pulsed laser so that the laser spot generated by the nanosecond pulsed laser is concentrated on the damaged coating area on the surface of the metal substrate for laser removal treatment.

[0058] Among them, the material of the damaged coating includes Inconel 625 material, and the thickness of the damaged coating is 100 μm; the working parameters include laser power, laser pulse width, line spacing, laser frequency, laser wavelength, scanning rate, scanning path, and scanning times. The laser power is 200 W, the laser pulse width is 15 ns, the line spacing is 0.015 mm, the laser frequency is 3000 kHz, the laser wavelength is 1064 nm, the scanning rate is 40 mm / s, the scanning path is a "hexagon" shape, and the scanning times are 2 times; the laser scanning spacing of the laser is less than the diameter of the laser spot, the diameter of the laser spot is 80 μm, and the overlap rate of the laser spot is 65%.

[0059] (3) After the laser cleaning process in step (2) is completed, purge the surface of the metal substrate with air, and then naturally cool it to room temperature in the air to obtain the metal substrate after removing the damaged coating.

[0060] Figure 1 The optical comparison diagrams of the metal substrate provided in this embodiment before and after removing the damaged coating are shown. It can be seen from the figure that obvious rectangular pits appear on the surface of the material (right figure) after laser cleaning, indicating that the coating has been completely removed. The microstructure of the substrate surface has changed. The surface of the substrate inside the pits is rough, and many circular protrusions appear on the substrate surface.

[0061] Example 2

[0062] The coating on the surface of the metal substrate provided in this embodiment is prepared by atmospheric plasma thermal spraying of Inconel 625 metal wire material on a Q235 metal plate.

[0063] This embodiment provides a method for laser cleaning of a damaged coating on the surface of a metal substrate. The laser cleaning method includes the following steps:

[0064] (1) Place the metal substrate with a damaged coating on its surface directly below the laser head of a nanosecond pulsed laser, and keep the plane where the damaged coating is located parallel to the platform surface of the nanosecond pulsed laser. At the same time, control the surface of the metal substrate to be 25 cm away from the laser head.

[0065] (2) Determine the material type, thickness, and shape of the damaged coating on the surface of the metal substrate, and then determine the working parameters of the nanosecond pulsed laser so that the laser spot generated by the nanosecond pulsed laser is concentrated on the damaged coating area on the surface of the metal substrate for laser cleaning treatment.

[0066] Among them, the material of the damaged coating includes Inconel 625 material, and the thickness of the damaged coating is 300 μm; the working parameters include laser power, laser pulse width, line spacing, laser frequency, laser wavelength, scanning rate, scanning path, and number of scans. The laser power is 200 W, the laser pulse width is 10 ns, the line spacing is 0.01 mm, the laser frequency is 2500 kHz, the laser wavelength is 1064 nm, the scanning rate is 50 mm / s, the scanning path is a "hexagonal" shape, and the number of scans is 4 times; the laser scanning spacing of the laser is less than the diameter of the laser spot, the diameter of the laser spot is 80 μm, and the overlap rate of the laser spots is 70%.

[0067] (3) After the laser cleaning process in step (2) is completed, purge the surface of the metal substrate with air, and then naturally cool it to room temperature in the air to obtain the metal substrate after removing the damaged coating.

[0068] Figure 2 The figure shows the optical comparison diagrams of the metal substrate provided in this embodiment before and after removing the damaged coating. It can be seen from the figure that obvious rectangular pits appear on the surface of the material (right figure) after laser cleaning, indicating that the coating has been completely removed. The microstructure of the substrate surface has changed. The surface of the substrate inside the pits is rough, and many circular protrusions appear on the substrate surface.

[0069] Example 3

[0070] The coating on the surface of the metal substrate provided in this embodiment is prepared on a Q235 metal plate by atmospheric plasma thermal spraying of a metal-based ceramic mixed powder material; wherein, the metal-based ceramic mixed powder material includes Ni60A and Al2O3 with a mass ratio of 17:3. The mesh number of Ni60A is 400 mesh, and the mesh number of Al2O3 is 600 mesh.

[0071] This embodiment provides a method for laser removing a damaged coating on the surface of a metal substrate. The laser removing method includes the following steps:

[0072] (1) Place the metal substrate with a damaged coating on the surface directly below the laser head of a nanosecond pulsed laser, and keep the plane where the damaged coating is located parallel to the platform surface of the nanosecond pulsed laser. At the same time, control the surface of the metal substrate to be 25 cm away from the laser head.

[0073] (2) Determine the material type, thickness and shape of the damaged coating on the surface of the metal substrate, and then determine the working parameters of the nanosecond pulsed laser so that the laser spot generated by the nanosecond pulsed laser is concentrated on the damaged coating area on the surface of the metal substrate for laser removing treatment.

[0074] Among them, the material of the damaged coating is a metal-based ceramic material, and the thickness of the damaged coating is 250 μm; the working parameters include laser power, laser pulse width, line spacing, laser frequency, laser wavelength, scanning rate, scanning path and scanning times. The laser power is 200 W, the laser pulse width is 10 ns, the line spacing is 0.01 mm, the laser frequency is 2500 kHz, the laser wavelength is 1064 nm, the scanning rate is 50 mm / s, the scanning path is a "hexagonal" shape, and the scanning times are 3 times; the laser scanning spacing of the laser is less than the diameter of the laser spot, the diameter of the laser spot is 80 μm, and the overlap rate of the laser spots is 70%.

[0075] (3) After the laser removing treatment in step (2) is completed, blow the surface of the metal substrate with air, and then naturally cool it to room temperature in the air to obtain the metal substrate after removing the damaged coating.

[0076] Figure 3The optical comparison diagram of the metal substrate provided in this embodiment before and after the damaged coating is removed is shown. It can be seen from the figure that after laser cleaning, obvious rectangular pits appear on the surface of the material (right figure), indicating that the coating has been completely removed. The microstructure of the substrate surface has changed, the surface of the substrate inside the pit is rough, and many round protrusions appear on the surface of the substrate.

[0077] Comparative Example 1

[0078] The coating on the surface of the metal substrate provided in this comparative example is the same as that in Example 1.

[0079] This comparative example provides a method for removing a damaged coating on the surface of a metal substrate, the method comprising the following steps:

[0080] The metal substrate with damaged coating on the surface is placed in the sandblasting equipment. The distance between the nozzle of the sandblasting equipment and the metal substrate is 100 mm, and the angle between the nozzle and the substrate is 60°. The coating is removed by continuous sandblasting.

[0081] Figure 4 An optical comparison diagram of the metal substrate provided in this comparative example before and after the damaged coating is removed is shown. It can be seen from the figure that after sandblasting (right figure), the coating is not completely removed and a part of the coating remains; and during the removal process, the noise pollution is serious; compared with laser cleaning, the efficiency of sandblasting removal is low, the pollution is serious, and the cleaning effect is poor.

[0082] In summary, the laser cleaning method provided by the present invention is environmentally friendly and efficient. It can not only achieve precise control of the cleaning process, but also completely remove the damaged coating and avoid excessive cleaning or damage to the metal substrate. Moreover, for some thicker metal coatings or coatings that are difficult to remove in one go, laser cleaning can be repeated multiple times to gradually remove the damaged coating without damaging the substrate.

[0083] The applicant declares that the present invention illustrates the process method of the present invention through the above-mentioned embodiments, but the present invention is not limited to the above-mentioned process steps, that is, it does not mean that the present invention must rely on the above-mentioned process steps to be implemented. Those skilled in the art should understand that any improvement of the present invention, equivalent replacement of the raw materials selected by the present invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims

1. A laser removal method for damaged coating on the surface of a metal substrate, characterized in that: The laser cleaning method comprises the following steps: Obtain the thickness and shape of the damaged coating on the surface of the metal substrate, determine the working parameters of the laser, so that the laser spot generated by the laser is concentrated on the damaged coating area on the surface of the metal substrate, and perform laser cleaning treatment; The working parameters include laser power, laser pulse width, line spacing and laser frequency.

2. The laser cleaning method according to claim 1, characterized in that: The material of the damaged coating includes Inconel 625 material or metal-based ceramic material; Preferably, the damaged coating has a thickness of 100-300 μm.

3. The laser cleaning method according to claim 1 or 2, characterized in that: The laser comprises a nanosecond pulse laser; Preferably, the laser pulse width of the laser is 1-500ns, preferably 5-20ns.

4. The laser cleaning method according to any one of claims 1 to 3, characterized in that: The laser power is 150-250W; Preferably, the laser frequency is 1-5000 kHz, preferably 2000-2500 kHz.

5. The laser cleaning method according to any one of claims 1 to 4, characterized in that: The line spacing is 0.008-0.012 mm.

6. The laser cleaning method according to any one of claims 1 to 5, characterized in that: The laser scanning interval of the laser is smaller than the diameter of the laser spot; Preferably, the diameter of the laser spot is 60-100 μm.

7. The laser cleaning method according to any one of claims 1 to 6, characterized in that: The operating parameters of the laser also include scanning rate; Preferably, the scanning rate is 1-16000 mm / s, preferably 50-100 mm / s.

8. The laser cleaning method according to any one of claims 1 to 7, characterized in that: The working parameters of the laser also include scanning path and scanning times; Preferably, the scanning path comprises a zigzag or a zigzag shape; Preferably, the scanning number is 1-5 times.

9. The laser cleaning method according to any one of claims 1 to 8, characterized in that: The laser cleaning method comprises the following steps: (1) Place a metal substrate with a damaged coating on its surface directly under the laser head of the laser, and keep the plane where the damaged coating is located parallel to the platform surface of the laser, while controlling the surface of the metal substrate to be 20-30 cm away from the laser head; (2) determining the material type, thickness and shape of the damaged coating on the surface of the metal substrate, and then determining the operating parameters of the laser so that the laser spot generated by the laser is concentrated on the damaged coating area on the surface of the metal substrate for laser removal; The material of the damaged coating includes Inconel 625 material or metal-based ceramic material, and the thickness of the damaged coating is 100-300 μm; the working parameters include laser power, laser pulse width, line spacing, laser frequency, laser wavelength, scanning rate, scanning path and scanning times, the laser power is 150-250 W, the laser pulse width is 1-500 ns, the line spacing is 0.008-0.012 mm, the laser frequency is 1-5000 kHz, the laser wavelength is 1064 nm, the scanning rate is 1-16000 mm / s, the scanning path includes a zigzag or a zigzag, and the scanning times are 1-5 times; the laser scanning spacing of the laser is less than the diameter of the laser spot, the diameter of the laser spot is 60-100 μm, and the overlap rate of the laser spot is 65-75%; (3) After the laser cleaning treatment in step (2) is completed, the surface of the metal substrate is purged and then cooled to room temperature to obtain a metal substrate with the damaged coating removed.

10. Application of the laser cleaning method according to any one of claims 1 to 9 in the field of metal surface coating cleaning.

Images